The use of softeners to treat fabrics subsequent to a washing operation is a well-known laundering practice. Fabric softeners are, in the main, water-insoluble cationic materials that are incompatible with anionic detersive surfactants used in most fabric washing compositions. For that reason, the softening operation is generally carried out in the laundry rinse bath after the surfactant has been removed from the washing machine. This entails additional work for the user.
Formulators of fabric laundering compositions have long sought means whereby the fabric washing and softening could be done concurrently. Methods employing clay softeners, mixtures of clays and various amine materials and the like, are described in the following patents: German Pat. Nos. 29/64114.3, 28/57163.3, 24/39541.3, 23/34899.4 and EPO Nos. 80200570.2, 80200877.1 and 80201015.7. The use of mixtures of amines and soaps (salts of fatty acids) as through-the-wash softeners is disclosed in U.K. Pat. No. 1 514 276.
The prior art also describes the use of various cationic materials in sheet form. See U.S. Pat. No. 4,220,562.
The present invention employs a water soluble quaternary ammonium salt in an otherwise conventional spray-dried detergent composition matrix, and clay, to provide cleaning and softening concurrently, through-the-wash. The quaternary ammonium salts used herein provide improved softening and anti-static benefits, especially when applied to polyester fabrics and/or when the compositions herein are used at relatively high laundering temperatures (60.degree. C., and above).